code: def test_croptobbox_3d():
      YXZ = np.indices((32, 32, 64), float)
      YXZ -= 8
      Y, X, Z = YXZ
      ball = ((X**2 + Y**2 + Z**2) < 64).astype(np.uint8)
      assert np.sum(ball) == np.sum(mh.croptobbox(ball))
  
file_path: mahotas/mahotas/tests/test_bbox.py
imports: import numpy
  import mahotas
  import mahotas
  from mahotas import bbox
label_desc: Use image node_id 2 for calling a global function with example usage: test_croptobbox_3d() without return types